Guide wire tip having roughened surface

ABSTRACT

A guidewire for use in penetrating through complex and stenosed lesions. The distal tip of the guidewire has a roughened surface to increase frictional engagement with calcified and fibrous tissue to increase the penetration of the distal tip and the guidewire into and through the lesion and reduce the likelihood of deflection of the guidewire tip. The average surface roughness of the distal tip is in the range from 1 micron to 200 microns.

BACKGROUND

The present invention generally relates to guidewires, and inparticular, the accurate positioning and delivery of a guidewire forpassing through a chronic total occlusion (“CTO”) of a body vessel.

A CTO is a severe narrowing of a blood vessel, such as a coronaryartery, that results in a complete or nearly complete occlusion of theprimary vessel. CTOs are quite common in diseased coronary arteries andtypically occur where plaque is formed in the artery, gradually reducingthe size of the lumen in the artery until it becomes quite small andresults in thrombus formation resulting in a stenosis forming a totalocclusion. As the total occlusion becomes chronic, the stenosis orblockage generally has a tendency to continue to grow with fibrous endcaps being formed at the proximal and distal ends of the occlusion.These fibrous end caps tend to be fairly tough but do have varyingdegrees of toughness.

Angioplasty and stent implantation procedures are commonly employed totreat CTOs or other stenoses that form within the vascular anatomy of apatient. During an angioplasty, or percutaneous transluminal coronaryangioplasty (“PTCA”) procedure, a guiding catheter is advanced throughthe vasculature of the patient to a desired point. A guidewire,positioned within a balloon catheter, is extended from a distal end ofthe guiding catheter into the patient's coronary artery until itpenetrates and crosses a blockage to be dilated. The balloon catheter isthen advanced through the guiding catheter and over the previouslyintroduced guidewire, until it is properly positioned across theblockage. Once properly positioned, the balloon is inflated to apredetermined size such that the material causing the blockage iscompressed against the arterial wall, thereby expanding the passagewayof the artery. The balloon is subsequently deflated, blood flow resumesthrough the dilated artery, and the balloon catheter is removed.Typically, a stent is implanted to maintain vessel patency.

In attempting to treat such chronic occlusions, there is a need to haveguidewires which can extend through the stenoses forming the chronicocclusions so that various types of treatments can be performed.Heretofore attempts to place guidewires across such stenoses orblockages have resulted in the guidewires following fissures in theplaque and creating false lumens or with the guidewire being directed insuch a manner so as to perforate the wall of the vessel causing a vesseldissection. In attempting to perform such a guidewire crossing, it oftenhas been necessary to exchange the guidewire for a stiffer wire, whichis time consuming.

In light of the above discussion, a need exists in the art for aguidewire tip designed to penetrate through complex and stenosed lesionsand configured for use with multiple guidewires employed in treatingintravascular blockages. Any solution to the above need should increasethe likelihood of a successful crossing of a CTO. Moreover, any proposedsolution should be adaptable for use with a variety of guidewire typesand configurations.

SUMMARY OF THE INVENTION

The present invention is directed to an improved guidewire providingenhanced distal support while having a flexible distal tip to provideacceptable steerability and little risk of damage to vessel or chamberlinings when advanced through a patient's body lumen such as veins andarteries.

The guidewire of the present invention has an elongated core member withproximal and distal core sections and a flexible tubular body such as ahelical coil disposed about and secured to the distal section of thecore member.

The flexible tubular body such as a helical coil is secured by itsdistal end to the distal end of the distal core section in aconventional fashion. The helical coil may be secured by its distal endby soldering, brazing, gluing or welding to form a rounded distal tip tothe guiding member as done with commercially available guidewires forprocedures within a patient's coronary artery. In one embodiment, thesoldered distal tip is roughened so that the outer surface of the distaltip has an average surface roughness no greater than 200 microns. Theroughened distal tip engages the stenosed lesion (CTO) and has increasedfriction which ensures that the roughened distal tip more easilypenetrates the stenosed lesion rather than deflecting off of it. In oneembodiment, the roughened distal tip has an average surface roughness inthe range from 1 micron to 10 microns. In another embodiment, theroughened distal tip has an average surface roughness in the range from20 microns and 150 microns. In another embodiment, the roughened distaltip has an average surface roughness in the range from 1 micron to 200microns.

These and other advantages of the invention will become more apparentfrom the following detailed description of the invention when taken inconjunction with the accompanying exemplary drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an elevational view partially in section of a guidewireembodying features of the invention.

FIG. 2 is a transverse cross-sectional view of the guidewire shown inFIG. 1 taken along lines 2-2.

FIG. 3 is an enlarged elevational view partially in section of thedistal portion of the guidewire shown in FIG. 1 depicting the tapers ofthe distal core section.

FIG. 4 is a micro-photograph of an elevational view of the distal endand distal tip of a guidewire depicting the rounded, half-dome shape ofthe distal tip before being modified.

FIGS. 5A and 5B are micro-photographs of an elevational view of theroughened surface of the distal tip and wire coils of the guidewire ofFIG. 4.

FIG. 6 is an elevational view of the distal end of the guidewireadvancing distally in a vessel and the roughened distal tip penetratingthrough a stenosed lesion.

FIG. 7A is a side view of a conically-shaped distal tip.

FIG. 7B is a front perspective view of the conically-shaped distal tipdepicting a recessed portion.

FIG. 7C is a rear perspective view of the conically-shaped distal tip.

FIG. 7D is a rear view of the conically-shaped distal tip depicting acavity.

FIG. 7E is a cross-sectional view taken along lines 7E-7E of the distaltip depicting the recessed portion and the cavity.

FIG. 8A is side view of a conically-shaped distal tip.

FIG. 8B is a front perspective view of the conically-shaped distal tip.

FIG. 8C is a rear perspective view of the conically-shaped distal tipdepicting a cavity.

FIG. 8D is a rear view of the conically-shaped distal tip depicting thecavity.

FIG. 8E is a cross-sectional view taken along lines 8E-8E of the distaltip depicting the cavity.

FIG. 9A is a side view of a frusto-conical-shaped distal tip.

FIG. 9B is a front perspective view of the frusto-conical-shaped distaltip depicting a recessed portion.

FIG. 9C is a rear perspective view of the frusto-conical-shaped distaltip depicting a cavity.

FIG. 9D is a rear view of the frusto-conical-shaped distal tip depictingthe cavity.

FIG. 9E is a cross-sectional view taken along lines 9E-9E of the distaltip depicting the recessed portion and the cavity.

FIG. 10A is a side view of one embodiment of the distal tip depicting afrusto-conical-shaped section and a stem extending therefrom.

FIG. 10B is a front perspective view of the embodiment of FIG. 10Adepicting a recessed portion.

FIG. 10C is a rear perspective view of the embodiment of FIG. 7Adepicting the stem portion.

FIG. 10D is a rear view of the embodiment of FIG. 10A depicting the stemportion.

FIG. 10E is a cross-sectional view taken along lines 10E-10E of thedistal tip depicted in FIG. 7A showing the recessed portion and the stemportion.

FIG. 11A is a side view of a mushroom-shaped distal tip.

FIG. 11B is a front perspective view of the mushroom-shaped distal tip.

FIG. 11C is a rear perspective view of the mushroom-shaped distal tipdepicting a stem portion.

FIG. 11D is a rear view of the mushroom-shaped distal tip depicting thestem portion.

FIG. 11E is a cross-sectional view taken along lines 11E-11E of themushroom-shaped distal tip depicting the stem portion.

FIG. 12A is a side view of a frusto-conical-shaped distal tip having astem portion and having arcuate grooves.

FIG. 12B is a front perspective view of the embodiment shown in FIG.12A.

FIG. 12C is a rear perspective view of the embodiment depicted in FIG.12A showing the stem portion.

FIG. 12D is a rear view of the embodiment of FIG. 12A depicting the stemportion and the arcuate grooves.

FIG. 12E is a cross-sectional view taken along lines 12E-12E of theembodiment of FIG. 12A depicting the stem portion and the arcuategrooves.

FIG. 13A is a side view of another embodiment of the distal tip.

FIG. 13B is a front perspective view of the embodiment of FIG. 13Adepicting a recessed portion.

FIG. 13C is a rear perspective view of the embodiment of FIG. 13Adepicting a stem portion.

FIG. 13D is a rear view of the embodiment of the FIG. 13A depicting thestem portion.

FIG. 13E is a cross-sectional view of taken along lines 13E-13E of theembodiment of FIG. 13A depicting the recessed portion and the stemportion.

FIG. 14A is a side view of another embodiment of the distal tip.

FIG. 14B is a front perspective view of the embodiment of FIG. 14Adepicting a through-hole.

FIG. 14C is a rear perspective view of the embodiment of FIG. 14Adepicting the through-hole.

FIG. 14D is a rear view of the embodiment of FIG. 14A depicting thethrough-hole.

FIG. 14E is a cross-sectional view taken along lines 14E-14E of theembodiment of FIG. 14A depicting the through-hole.

FIG. 15A is a side view of an angulated distal tip.

FIG. 15B is a front perspective view of the angulated distal tip havinga recessed portion and a stem portion.

FIG. 15C is a rear perspective view of the angulated distal tipdepicting the stem portion.

FIG. 15D is a rear view of the angulated distal tip depicting the stemportion.

FIG. 15E is a cross-sectional view taken along lines 15E-15E of theangulated distal tip depicting the recessed portion and the stemportion.

FIG. 16A is a side view of another embodiment of the distal tip.

FIG. 16B is a front perspective view of the embodiment of FIG. 16Adepicting a recessed portion.

FIG. 16C is a rear perspective view of the embodiment of FIG. 16Adepicting a cavity.

FIG. 16D is a rear view of the embodiment of FIG. 16A depicting thecavity.

FIG. 16E is a cross-sectional view taken along lines 16E-16E of theembodiment of FIG. 16A depicting the recessed portion and the cavity.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIGS. 1-3 depict a guidewire 10 which is a presently preferredembodiment thereof which has a core member 11 with a proximal coresection 12, a distal core section 13 and a helical coil 14. The distalcore section 12 has a first tapered segment 15 and a second tapered coresegment 16 which is distally contiguous to the first tapered coresegment. The second tapered segment 16 tapers at a greater degree thanthe first tapered segment and this additional taper provides a muchsmoother transition when the distal portion of the guidewire 10 isadvanced through a tortuous passageway. The degree of taper of the firsttapered core segment 15, i.e., the angle between the longitudinal axis17 and a line tangent to the first tapered core segment 15 typically isabout 2° to about 10°, whereas the taper of the second tapered coresegment 16, i.e., the angle between the longitudinal axis and the secondtapered core segment is larger than the first angle and typically isabout 5° to about 10° such as is shown in the enlarged view of theguidewire 10 in FIG. 3. While only two tapered core segments are shownin the drawings, any number of tapered core segments can be employed.Moreover, all of a multiple of tapered core segments need not haveincreasing degrees of tapers in distal direction. However, two or morecontiguous tapered core segments over a length of about 5 to 15 cmshould have distally increasing degrees of tapering.

Typically, the first tapered segment is about 3 cm in length and thesecond tapered segment is about 4 cm in length. In a presently preferredembodiment, the guidewire 10 has a proximal core section 12 of about0.014 inch (0.36 mm) in diameter, the first tapered core segment has adiameter ranging from 0.014 inch down to about 0.008 inch (0.36-0.20 mm)and the second tapered core segment has a diameter ranging from about0.008 inch to about 0.002 inch (0.20-0.05 mm). A flattened distalsection 18 extends from the distal end of the second tapered coresegment 16 to the distal tip 20, which secures the distal section 18 ofthe core member 11 to the distal end 19 of the helical coil 14. A bodyof solder 21 secures the proximal end of the helical coil 14 to anintermediate location on the second tapered segment 16.

The core member 11 is coated with a lubricious coating 22 such as afluoropolymer, e.g., TEFLON® available from DuPont, which extends thelength of the proximal core section 12. The distal section 13 is alsoprovided a lubricous coating, not shown for purposes of clarity, such asa MICROGLIDE™ coating used by the present assignee, AbbottCardiovascular Systems, Inc., on many of its commercially availableguidewires. A hydrophilic coating may also be employed.

The core member may be formed of stainless steel, NiTi alloys orcombinations thereof or other high strength alloys as is well known inthe art.

The helical coil 14 is formed of a suitable radiopaque material such asplatinum or alloys thereof or formed of other material such as stainlesssteel and coated with a radiopaque material such as gold. The wire fromwhich the coil is made generally has a transverse diameter of about0.003 inch (0.05 mm). The overall length of the helical coil 14 istypically about 3 cm. Multiple turns of the distal portion of coil 14may be expanded to provide additional flexibility.

In keeping with the invention and as shown in FIGS. 1-6, a guidewire 10has an elongated core member 11 having a proximal core section 12 and adistal core section 13. The distal core section 13 has a distal end 24which typically has a helical coil 14 mounted thereon. A distal tip 20is mounted on the distal end 24 and is attached to the helical coil 14.In one embodiment, as shown in FIGS. 4-5B, the distal tip 20 is formedfrom a body of solder 21 and formed into a half-dome shape 26 on thedistal end 24. Since the body of solder typically is smooth when formed,the distal tip 20 is treated to form a roughened surface 28. Theroughened surface 28 is used to more easily penetrate calcified andfibrous tissue or lesions (chronic total occlusion CTO) by increasingthe friction between the roughened surface 28 and the lesion. When thedistal tip 20 is smooth as seen in FIG. 4, it has a tendency to slideoff of the calcified lesion and fail to penetrate the lesion. Theroughened surface 28 of FIGS. 5A and 5B will more easily penetrate thecalcified lesion because the roughened surface sticks to the lesion andwill not deflect or slide away, allowing the physician to advance theguidewire through the lesion. In the embodiment of FIG. 5A, the body ofsolder was micro bead blasted with aluminum oxide media while mounted onthe distal end 24 to form the roughened surface 28. In the embodiment ofFIG. 5B, the body of solder was micro bead blasted with sodiumbicarbonate media while mounted on the distal end 24 to form theroughened surface 28. In one embodiment, the average surface roughnessof the roughened surface 28 is in the range from 20 microns to 150microns. In one embodiment, the average surface roughness of theroughened surface 28 is in the range from 1 micron to 200 microns. Themicro bead blasting media is not limited to aluminum oxide and sodiumbicarbonate, rather any suitable abrasive media can be used. Themicro-blasting process disclosed herein is well known in the art andneed not be further described.

In another embodiment as shown in FIGS. 1-4, 6 and 7A-16E, a guidewire10 has an elongated core member 11 having a proximal core section 12 anda distal core section 13. The distal core section 13 has a distal end 24which typically has a helical coil 14 mounted thereon. A distal tip 20is mounted on the distal end 24 and is attached to the helical coil 14.In one embodiment, as shown in FIG. 4, the distal tip 20 is formed froma body of solder 21 and formed into a half-dome shape 26 on the distalend 24. Since the body of solder typically is smooth when formed, thedistal tip 20 is treated to form a roughened surface 28. The roughenedsurface 28 is used to more easily penetrate calcified and fibrous tissueor lesions (chronic total occlusion CTO) by increasing the frictionbetween the roughened surface 28 and the lesion. When the distal tip 20is smooth as seen in FIG. 4, it has a tendency to slide off of thecalcified lesion and fail to penetrate the lesion. The roughened surface28 of FIGS. 6 and 7A-16E will more easily penetrate the calcified lesionbecause the roughened surface sticks to the lesion and will not deflector slide away, allowing the physician to advance the guidewire throughthe lesion. In the embodiment of FIGS. 7A-16E, the body of solder wastreated by laser roughening to form the roughened surface 28. In theseembodiments, the average surface roughness of the laser roughenedsurface 28 is in the range of 1 micron to 10 microns. In one embodiment,the average surface roughness of the laser roughened surface 28 is inthe range from 1 micron to 200 microns.

Other surface treatments are contemplated to impart the disclosedsurface roughness 28 and include micro machining, sand paper, chemicaletching, wire brush, chemical vapor deposition, or physical vapordeposition.

While the roughened surface 28 of the distal tip 20 shown in FIGS. 5Aand 5B was formed by micro bead blasting while mounted on the distal end24, it might be more preferable to form the distal tip 20 with aroughened surface 28 before mounting the distal tip 20 onto the distalend 24. As shown in FIGS. 7A-16E, different embodiments of the distaltip are shown having different structural characteristics and prior tobeing treated to form a roughened surface and prior to being mounted onthe distal tip. The distal tips shown in FIGS. 7A-16E are manufacturedat a component level and then processed through surface preparation andattached to a guidewire, as further disclosed herein.

In one embodiment, as shown in FIGS. 7A-7E, a conically-shaped distaltip 30 has a generally conical surface 31. A recess 32 is formed in thedistal end 33 of the conically-shaped distal tip 30 and is configured toprovide an edge 34 that will hold the distal tip 30 in place when therecess engages hard plaque. At a proximal end 35 of the distal tip 30, acavity 36 is formed which is configured for mounting on the distal end24 of the distal core section 13 (see FIG. 3). The roughened surface 28increases the frictional engagement of the distal tip with the hardenedplaque with an increased likelihood that the distal tip willsuccessfully advance through the plaque.

In another embodiment, as shown in FIGS. 8A-8E, a conically-shapeddistal tip 40 has a generally conical surface 41. A slightly roundednose cone 42 is formed in the distal end 43 of the conically-shapeddistal tip 40 and is configured to provide an projection 44 that willhold the distal tip 40 in place when the projection 44 engages hardplaque. At a proximal end 45 of the distal tip 40, a cavity 46 is formedwhich is configured for mounting on the distal end 24 of the distal coresection 13 (see FIG. 3). The roughened surface 28 increases thefrictional engagement of the distal tip with the hardened plaque with anincreased likelihood that the distal tip will successfully advancethrough the plaque.

In another embodiment, as shown in FIGS. 9A-9E, a frusto-conical-shapeddistal tip 50 has a generally conical surface 51. A recess 52 is formedin the distal end 53 of the frusto-conical-shaped distal tip 50 and isconfigured to provide an edge 54 that will hold the distal tip 50 inplace when the recess 52 engages hard plaque. At a proximal end 55 ofthe distal tip 50, a cavity 56 is formed which is configured formounting on the distal end 24 of the distal core section 13 (see FIG.3). The roughened surface 28 increases the frictional engagement of thedistal tip with the hardened plaque with an increased likelihood thatthe distal tip will successfully advance through the plaque.

In another embodiment, as shown in FIGS. 10A-10E, afrusto-conical-shaped distal tip 60 has a generally conical surface 61.A recess 62 is formed in the distal end 63 of the frusto-conical-shapeddistal tip 60 and is configured to provide an edge 64 that will hold thedistal tip 60 in place when the recess 62 engages hard plaque. At aproximal end 65 of the distal tip 60, a stem 66 is formed which isconfigured for inserting into and mounting on the distal end 24 of thedistal core section 13 by inserting into the helical coil 14 (see FIG.3). The roughened surface 28 increases the frictional engagement of thedistal tip with the hardened plaque with an increased likelihood thatthe distal tip will successfully advance through the plaque.

In another embodiment, as shown in FIGS. 11A-11E, a mushroom-shapeddistal tip 70 has a generally conical surface 71. A rounded nose cone 72is formed in the distal end 73 of the conically-shaped distal tip 70 andis configured to provide a projection 74 that will hold the distal tip70 in place when the rounded nose cone 72 engages hard plaque. At aproximal end 75 of the distal tip 70, a stem 76 is formed which isconfigured for inserting into and mounting on the distal end 24 of thedistal core section 13 by inserting into the helical coil 14 (see FIG.3). The roughened surface 28 increases the frictional engagement of thedistal tip with the hardened plaque with an increased likelihood thatthe distal tip will successfully advance through the plaque.

In another embodiment, as shown in FIGS. 12A-12E, afrusto-conical-shaped distal tip 80 has a generally conical surface 81.A recess 82 is formed in the distal end 83 of the frusto-conical-shapeddistal tip 80 and is configured to provide an edge 84 that will hold thedistal tip 80 in place when the recess 82 engages hard plaque. Multiplearcuate grooves 87 are formed into the conical surface 81 and areconfigured to bore into the hardened plaque like a drill bit when thephysician twists or spins the guidewire. Thus, by twisting the guidewireand pushing simultaneously, the physician can advance the distal tip 80and the arcuate grooves 87 into and through the plaque like a drill bit.At a proximal end 85 of the distal tip 80, a stem 86 is formed which isconfigured for inserting into and mounting on the distal end 24 of thedistal core section 13 by inserting into the helical coil 14 (see FIG.3). The roughened surface 28 increases the frictional engagement of thedistal tip with the hardened plaque with an increased likelihood thatthe distal tip will successfully advance through the plaque.

In another embodiment, as shown in FIGS. 13A-13E, a partiallyconically-shaped distal tip 90 has a generally conical surface 91. Arecess 92 is formed in the distal end 93 of the partiallyconically-shaped distal tip 90 and is configured to provide an edge 94that will hold the distal tip 90 in place when the recess 92 engageshard plaque. At a proximal end 95 of the distal tip 90, a stem 96 isformed which is configured for inserting into and mounting on the distalend 24 of the distal core section 13 by inserting into the helical coil14 (see FIG. 3). The roughened surface 28 increases the frictionalengagement of the distal tip with the hardened plaque with an increasedlikelihood that the distal tip will successfully advance through theplaque.

In another embodiment, as shown in FIGS. 14A-14E, a partiallyconically-shaped distal tip 100 has a generally conical surface 101. Athrough hole 102 is formed in the distal end 103 of the partiallyconically-shaped distal tip 100 and is configured to provide an edge 104that will hold the distal tip 100 in place when the edge 104 engageshard plaque. At a proximal end 105 of the distal tip 100, thethrough-hole 102 exits the distal tip 100 and is configured for mountingon the distal end 24 of the distal core section 13 (see FIG. 3). Theroughened surface 28 increases the frictional engagement of the distaltip with the hardened plaque with an increased likelihood that thedistal tip will successfully advance through the plaque.

In another embodiment, as shown in FIGS. 15A-15E, an angularly-shapeddistal tip 110 has a partially conical surface 111. A recess 112 isformed in the distal end 113 of the angularly-shaped distal tip 110 andis configured to provide an edge 114 that will hold the distal tip 110in place when the recess 112 engages hard plaque. The angularly-shapeddistal tip 110 is angled because typically a physician puts a slightbend (with finger pressure) at the end of the helical coil 14 so thatthe guidewire can be advanced in a particular direction. In treatingchronically stenosed lesions, a short angulation in the distal tip 110is desired. This embodiment provides a short or small angulation to thedistal tip 110 of the guidewire 10. At a proximal end 115 of the distaltip 110, a stem 116 is formed which is configured for inserting into andmounting on the distal end 24 of the distal core section 13 by insertinginto the helical coil 14 (see FIG. 3). The roughened surface 28increases the frictional engagement of the distal tip with the hardenedplaque with an increased likelihood that the distal tip willsuccessfully advance through the plaque.

In another embodiment, as shown in FIGS. 16A-16E, a partiallyconically-shaped distal tip 120 has a generally conical surface 121. Arecess 122 is formed in the distal end 123 of the partiallyconically-shaped distal tip 120 and is configured to provide an edge 124that will hold the distal tip 120 in place when the recess 122 engageshard plaque. At a proximal end 125 of the distal tip 120, a cavity 126is formed which is configured for mounting on the distal end 24 of thedistal core section 13 (see FIG. 3). The roughened surface 28 increasesthe frictional engagement of the distal tip with the hardened plaquewith an increased likelihood that the distal tip will successfullyadvance through the plaque.

In all of the disclosed embodiments, the purpose and intent is toincrease the surface roughness of the distal tip in order to enhanceengagement with calcified and fibrous tissue (CTO). Severalmanufacturing methods have been developed to increase the surfaceroughness of the distal tip. In one method, once the distal tip has beensoldered or otherwise attached to the guidewire distal end 24 orinserted into the helical coil 14, the distal tip is processed by microbead blasting, laser roughening, sand paper, micro machining, and wirebrushed to provide the desired level of surface roughness. Some of thesemanufacturing processes are easier to control than others, thus laserroughening is a preferred process because it is the most repeatable andmanufacturing friendly version, providing the most options on texturetype and degree of surface roughness.

In another manufacturing method, the distal tips can be manufactured ata component level and processed through surface preparation. These tipscan then be attached to the core wire and coils viasoldering/welding/adhesive or other suitable means. Tips can bemanufactured by, but not limited to, stamping, casting, machining, micromolding, metal injection molding, and 3D printing and then furtherprocessed through surface treatments such as bead blasting, laserroughening, machining, sand paper, chemical etching, chemical vapordeposition or physical vapor deposition. FIGS. 7A-16E show some of thetip designs which can be machined, surface prepped and attached to theguide wire.

While reference has been made herein to the distal tip 20 being formedfrom a body solder 21, the distal tip 20 can be formed from other metalalloys or from plastics or polymers.

I claim:
 1. A guidewire, comprising: an elongated core member having aproximal core section and a distal core section; a distal tip attachedto a distal end of the distal core section, the distal tip formed from ametallic alloy or polymer and having a roughened surface for use inpenetrating stenosed lesions in vessels.
 2. The guidewire of claim 1,wherein the roughened surface is formed by physically altering thesurface of the distal tip.
 3. The guidewire of claim 2, wherein thephysical alteration of the surface includes any of micro bead blasting,laser roughening, sand paper, micro machining, and wire brush.
 4. Theguidewire of claim 1, wherein an average surface roughness of the distaltip is in the range from 1 micron to 200 microns.
 5. The guidewire ofclaim 1, wherein an average surface roughness of the distal tip is inthe range from 1 micron to 10 microns.
 6. The guidewire of claim 1,wherein an average surface roughness of the distal tip is in the rangefrom 20 microns to 150 microns.
 7. The guidewire of claim 1, wherein thedistal tip abuts a wire coil, at least a distal portion of the wire coilhaving a roughened surface.
 8. The guidewire of claim 1, wherein thedistal tip is manufactured by any of stamping, casting, micro molding,machining, metal injection molding, and 3D printing.
 9. The guidewire ofclaim 1, wherein the roughened surface of the distal tip is formed byany of chemical etching, chemical vapor deposition, and physical vapordeposition.
 10. The guidewire of claim 1, wherein the distal tip has astructural configuration including any of rounded half-dome, conical,frusto-conical, mushroom-shaped, conical with a flattened tip, andconical with recessed tip.
 11. A method of manufacturing a distal tipfor attaching to a guidewire, comprising: forming a metal alloy orpolymer into a distal tip; roughening a surface of the distal tip foruse in penetrating stenosed lesions in a vessel.
 12. The method of claim11, wherein an average surface roughness of the distal tip is in therange from 1 micron to 200 microns.
 13. The method of claim 11, whereinan average surface roughness of the distal tip is in the range from 1micron to 10 microns.
 14. The method of claim 11, wherein an averagesurface roughness of the distal tip is in the range from 20 microns to150 microns.
 15. The method of claim 11, wherein roughening the surfaceof the distal tip includes any of micro bead blasting, laser roughening,applying sand paper, micro machining, and wire brushing.
 16. The methodof claim 11, wherein the distal tip is formed by any of stamping,casting, micro molding, machining, metal injection molding and 3Dprinting.
 17. The method of claim 11, wherein roughening the surface ofthe distal tip includes any of chemical etching, chemical vapordeposition, and physical vapor deposition.
 18. The method of claim 11,wherein the distal tip abuts a wire coil, and simultaneously rougheningat least a portion of the wire coil and the distal tip.